/Engine/Source/Runtime/Slate/Public/Framework/MultiBox/MultiBoxExtender.h
Extends a menu bar at the specified extension point
Pointer to the new extension object. You can use this later to remove the extension.
[TSharedRef](API\Runtime\Core\Templates\TSharedRef)< const FExtensionBase > AddMenuBarExtension ( [FName](API\Runtime\Core\UObject\FName) ExtensionHook, [EExtensionHook::Position](API\Runtime\Slate\Framework\MultiBox\EExtensionHook__Position) HookPosition, const [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FUICommandList](API\Runtime\Slate\Framework\Commands\FUICommandList) > & CommandList, const FMenuBarExtensionDelegate & MenuBarExtensionDelegate )